With the continuous improvement of market demand, projectors with high brightness, large size and high resolution have received more and more attention from the market. The laser light source is applied to projector technologies because of its high luminous power per unit area, long service life and good color. However, due to characteristics such as immaturity technology and low efficiency of green laser arrays, phosphors are usually used in the laser light source, and fluorescence with a color such as green is emitted through laser excitation of the phosphors, thereby providing a projector with red light (R light), green light (G light) and blue light (B light).
At present, a laser projection device commonly used, as shown in FIG. 1, includes a laser array 1; a diffusion sheet 2 disposed in a light emitting direction of the laser array 1; and a dichroscope 3 disposed in a light emitting direction of the diffusion sheet 2 and forming a 45° angle with the light emitting direction of the diffusion sheet 2; a fluorescent wheel 5 disposed in a light emitting direction of the dichroscope 3, where the fluorescent wheel 5 is provided with a laser transmission region and a phosphor-coated fluorescent region; a relay loop 7 disposed around the fluorescent wheel 5, where the relay loop 7 is a light path conversion system consisting of three lenses and three reflectors; and a color filter wheel 8 disposed on a side of the dichroscope 3 and disposed parallel to the light emitting direction of the laser array 1; and a homogenization component 9 disposed in a light emitting direction of the color filter wheel 8. In addition, two collimation components are further included, where a collimation component 4 is disposed between the dichroscope 3 and the fluorescent wheel 5, and a collimation component 6 is disposed between the fluorescent wheel 5 and the relay loop 7. In use, the laser emitted from the laser array 1, after passing through the diffusion sheet 2, forms a circular Gaussian beam, which passes through the dichroscope 3 to be irradiated onto the rotated fluorescent wheel 5 after being collimated by the collimation component 4. When the laser is irradiated to the laser transmission region, the laser passing through the laser transmission region is steered by the relay loop 7 after being collimated by the collimation unit 6, and enters into the homogenization component 9 for homogenization via the color filter wheel 8. When the laser is irradiated to the fluorescent region, the fluorescent region is excited by the laser to emit a fluorescent light, and the excited fluorescent light is irradiated to the dichroscope 3 after passing through the collimation component 4, which is reflected by the dichroscope 3 to the color filter wheel 8 for filtration, and the filtered fluorescent light also enters into the homogenization component 9 for homogenization, and then is collimated by the collimating lens 10. As the fluorescent wheel 5 rotates, a square spot of laser and fluorescent light is continuously obtained from the light output of the collimating lens 10. The laser and the fluorescent light emitted from the collimating lens 10 are imaged on a display chip of a light machine, and finally an image output is achieved through the lens 13. The display chip may be one of a Liquid Crystal Display (LCD) chip, a Digital Micromirror Device (DMD) chip and a Liquid Crystal on Silicon (LCOS) chip. Taking a light machine part composed of the DMD chip as an example, the laser projection device comprise a light source part and the light machine part, the laser and fluorescent light emitted from the light source part are transmitted to the interior of the light machine, a total reflection occurs on a first inclined surface 121 of a total internal reflection (TIR) prism group 12 inside the light machine with reflections to the DMD 11, and finally an image output is achieved via the imaging lens 13.